Kepler connected for home runs his first two times up Saturday night against Cleveland's hard-throwing starter, giving the Minnesota outfielder five homers in five straight at-bats against the right-hander.
Kepler homered three times off Bauer in Minnesota's win June 6 and also drew a walk.
He made it four homers in four straight at-bats with a leadoff shot Saturday night then connected in the second inning, one batter after rookie Jake Cave homered off Bauer.
Bauer finally got the best of Kepler in the fourth inning, striking him out, but only after Kepler hit a deep foul ball into the upper deck in right. He finished the night 2-for-5 as the Twins beat the Indians 6-2 to move 7½ games ahead of Cleveland in the American League Central.
According to the Elias Sports Bureau, Kepler matched the longest streak in the expansion era for homers in consecutive at-bats against one pitcher. Carlos Delgado did it against Jorge Sosa (2003-04), and Frank Howard connected against Bob Hendley (1963-64).
After the game, Kepler didn't make much of his achievement.
"Every pitcher is the same,'' Kepler said. "I have the same approach. I just try to simplify it when I go up there.''
Minnesota manager Rocco Baldelli was more effusive in his praise.
"It's unfathomable that it's happening right in front of our eyes,'' Baldelli said. "Nobody has seen anything like it.''
Kepler has 13 career homers against the Indians, including 11 at Progressive Field. He also had a three-homer game in Cleveland as a rookie in 2016.
Saturday marked Kepler's fourth multihomer game of the season, matching his total from the previous three seasons.
Kepler's five home runs vs. Bauer are his most against any pitcher in his career and the most by a batter against Bauer in the pitcher's career.
"I don't know,'' Bauer said. "How do you explain it? It's just one of those baseball things ... He's just locked in against me -- for whatever reason. It won't be that way forever. He'll cool down, and he'll go through a 0-for-10 with seven punchouts or whatever and miss pitches. It's just one of those things right now.''
ESPN Stats & Information and The Associated Press contributed to this report.